Venous thromboembolism heparins

Patients with cancer who develop a venous thromboembolism may benefit from long-term therapy with a low molecular weight heparin (at least the first 3-6 mo of pharmacotherapy) instead of oral warfarin... 

DVT, deep vein thrombosis HIT, heparin-induced thrombocytopenia PAI-I, plasminogen activator inhibitor PE, pulmonary embolism SERM, selective estrogen receptor modulator VTE, venous thromboembolism. 

FIGURE 7-4. Coagulation cascade. AT, antithrombin HCII, heparin cofactor II TFPI, tissue factor pathway inhibitor. (Reproduced from Haines ST, Zeolla M, Witt DM. Venous thromboembolism. In ... 

FIGURE 7-5. Treatment approach for patients with VTE. INR, International Normalized Ratio IV, intravenous LMWH, low-molecular-weight heparin PO, oral SC, subcutaneous UFH, unfractionated heparin VTE, venous thromboembolism. (Adapted from Nutescu EA. Emerging options in the treatment of venous thromboembolism. Am J Health Syst Pharm 2004 61 (Suppl 7) S16, with permission.)... 

Low-molecular-weight heparins and heparinoids are not recommended in the treatment of acute ischemic stroke.11 A meta-analysis was performed using data from 10 randomized controlled trials.19 A non-significant decrease in combined death and disability and a non-significant increase in case fatality and hemorrhage were seen. A reduction in venous thromboembolic events was observed in acute stroke patients however, there was also an increase in extracranial bleeding. 

Pineo, G. and Hull, R. 1997. Low molecular weight heparin-prophylaxis and treatment of venous thromboembolism. Annual Review of Medicine 48, 79-91. 

FIGURE 14-2. Treatment of venous thromboembolism (VTE). (LMWH, low-molecular-weight heparin PE, pulmonary embolism SBP, systolic blood pressure UFH, unfractionated heparin.)... 

Cancer is a complicated process consisting of well-coordinated multiple steps. Randomized trials to study the effectiveness of LMW heparins as compared with unfractionated heparin in treating venous thromboembolism in cancer patients led to a surprising observation that treatment with heparin... 

Wittkowsky AK. Why warfarin and heparin need to overlap when treating acute venous thromboembolism. Dis Mon 2005 51 112-5. 

Warfarin readily crosses the placenta. It can cause hemorrhage at any time during pregnancy as well as developmental defects when administered during the first trimester. Therefore, venous thromboembolic disease in pregnant women is generally treated with heparin, best administered by subcutaneous injection. 

Bergqvist D. Low-molecular-weight heparin for the prevention of postoperative venous thromboembolism after abdominal surgery a review. Curr Opin Pulm Med. 2005 11 392-397. 

Kher A, Samama MM. Primary and secondary prophylaxis of venous thromboembolism with low-molecular-weight heparins prolonged thromboprophylaxis, an alternative to vitamin K antagonists. J Thromb Haemost. 2005 3 473-481. 

Matsagas MI. Outpatient treatment of venous thromboembolism using low molecular weight heparins. An overview. IntAngiol. 2004 23 305-316. 

Pineo GF, Hull RD. Low-molecular-weight heparin for the treatment of venous thromboembolism in the elderly. Clin Appl Thromb Hemost. 2005 11 ... 

Currently several dermatan sulfates are under development for the prophylaxis of venous thromboembolism. While similar in stmcture to heparin, these agents do not produce any effect on platelets. Furthermore, these agents ate poorly absorbed after subcutaneous administration. More recently some low molecular weight dermatans have been produced which ate absorbed subcutaneously, unlike dermatan sulfete. 

Cost-effectiveness analysis is concerned with how to attain a given objective at minimum financial cost, e.g. prevention of postsurgical venous thromboembolism by heparins, warfarin, aspirin, external pneumatic compression. Analysis includes cost of materials, adverse effects, any tests, nursing and doctor time, duration of stay in hospital (which may greatly exceed the cost of the drug). 

The convenience (and cost-effectiveness) of LMW heparin therapy has resulted in widespread changes in practice. Patients with acute venous thromboembolism can be treated safely and effectively with LMW heparin as outpatients. Large-scale studies have demonstrated that outpatient treatment of acute deep vein thrombosis (DVT) with unmonitored body-weight adjusted LMW heparin is as safe and effective as inpatient treatment with adjusted dose intravenous standard heparin. Further trials have confirmed the safety and efficacy of LMW heparin therapy in acute pulmonary embolism and that 80% of imselected patients with acute thromboembolism can be safely treated as outpatients. ... 

Low-dose unfractionated heparin or LMW heparin can be used to prevent venous thromboembolism in other high-risk patients, e.g. those confined to bed and immobilised with strokes, cardiac failure or malignant disease. Spontaneous bleeding has not been a problem with this form of anticoagulant treatment. 

Acute myocardial infarction. Anticoagulation with heparin is used to reduce the risk of venous thromboembolism, and the risk and size of emboli from mural thrombi following acute myocardial infarction. 

Venous thromboembolism is the most common presentation of HIT, although arterial events (e.g., myocardial infarction and stroke) can occur. HIT should be suspected if a patient develops a DVT or PE while or soon after receiving unfractionated heparin. 

Dolovich L, Ginsberg JS, Douketis J, et al. A meta-analysis comparing low-molecular-weight heparins with unfractionated heparin in the treatment of venous thromboembolism. Arch Intern Med 2000 160 181-188. 

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